Fluid clients get out of sync when server is rebooted - fluid-framework

Question

I got the HelloWorld example to run fine. But once I stopped & restarted the server the clients got out of sync--even when I set a consistent document (i.e. location.hash = "12345").
Setting createNew=false broke the app (no dice--literally).
And I get a lot of repeating errors:
[start:server] error: Connect Document error: {} {"messageMetaData":{"documentId":"1608237690408","tenantId":"tinylicious"},"label":"winston","timestamp":"2020-12-17T20:45:13.160Z"}
[start:server] info: Disconnect of 60c72737-3e05-4bc7-bf9b-f7ca6439a431 from room {"messageMetaData":{"documentId":"1608237690408","tenantId":"tinylicious"},"label":"winston","timestamp":"2020-12-17T20:45:13.161Z"}
Does Fluid support this scenario? Or am I doing something wrong?

Answer 1

The tinylicious service could support turning off & on with durable data, but it's really meant to be a test service. When you restart the service, you'll probably want to pick a new documentID.
createNew is a more interesting story. The Hello World application is somewhat contrived example. In general, the app developer will get a signal from the user that a new document should be created. Think about Google Docs.
"Create New Google Doc" -> createNew === true
"Open existing Google Doc" -> createNew === false
However, for the Hello World scenario, we want to have as little code as possible. We certainly don't want to write out a whole document management schema. So we rely on a nifty little trick: If you paste in a URL with a specific documentID we assume you are loading an existing document, otherwise we will make a new one for you.
That's what the below is doing!
You'll see the effects in the URLs, which look something like this: http://localhost:8080/#1608592296522
let createNew = false;
if (location.hash.length === 0) {
createNew = true;
location.hash = Date.now().toString();
}
const documentId = location.hash.substring(1);
document.title = documentId;